全文获取类型
收费全文 | 53482篇 |
免费 | 5392篇 |
国内免费 | 3784篇 |
专业分类
耳鼻咽喉 | 506篇 |
儿科学 | 469篇 |
妇产科学 | 506篇 |
基础医学 | 5498篇 |
口腔科学 | 801篇 |
临床医学 | 6849篇 |
内科学 | 7328篇 |
皮肤病学 | 394篇 |
神经病学 | 2589篇 |
特种医学 | 2223篇 |
外国民族医学 | 22篇 |
外科学 | 5831篇 |
综合类 | 10582篇 |
现状与发展 | 6篇 |
一般理论 | 6篇 |
预防医学 | 4074篇 |
眼科学 | 1486篇 |
药学 | 5821篇 |
62篇 | |
中国医学 | 3619篇 |
肿瘤学 | 3986篇 |
出版年
2024年 | 272篇 |
2023年 | 957篇 |
2022年 | 2409篇 |
2021年 | 3051篇 |
2020年 | 2432篇 |
2019年 | 1851篇 |
2018年 | 1971篇 |
2017年 | 1807篇 |
2016年 | 1795篇 |
2015年 | 2694篇 |
2014年 | 3315篇 |
2013年 | 3219篇 |
2012年 | 4775篇 |
2011年 | 4886篇 |
2010年 | 3470篇 |
2009年 | 2766篇 |
2008年 | 3019篇 |
2007年 | 2970篇 |
2006年 | 2693篇 |
2005年 | 2431篇 |
2004年 | 1555篇 |
2003年 | 1372篇 |
2002年 | 1111篇 |
2001年 | 867篇 |
2000年 | 755篇 |
1999年 | 785篇 |
1998年 | 462篇 |
1997年 | 465篇 |
1996年 | 376篇 |
1995年 | 322篇 |
1994年 | 284篇 |
1993年 | 169篇 |
1992年 | 178篇 |
1991年 | 161篇 |
1990年 | 156篇 |
1989年 | 130篇 |
1988年 | 122篇 |
1987年 | 106篇 |
1986年 | 90篇 |
1985年 | 72篇 |
1984年 | 57篇 |
1983年 | 42篇 |
1982年 | 25篇 |
1981年 | 19篇 |
1980年 | 21篇 |
1979年 | 16篇 |
1978年 | 17篇 |
1976年 | 13篇 |
1975年 | 11篇 |
1969年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Pain is one of the most distressing symptoms associated with cancer. Basic science research has provided much insight into the mechanisms of peripheral and central pain and the actions of new drugs. Despite these advances, pain accompanying malignancy can be difficult to treat. Pain most commonly presents when the tumor has invaded somatic,visceral, or neural structures. An understanding of pain mechanisms is essential when deciding on the appropriate treatment. New therapeutic options have been developed and will hopefully provide clinicians with tools to successfully alleviate cancer pain. 相似文献
82.
Chan CC Factor V Li Q Nagy P Peng B Thorgeirsson SS 《Ocular immunology and inflammation》1996,4(4):183-191
Transforming growth factor-beta (TGFsZ) is a potent regulator of cellular growth and immune function. The authors studied ocular histology and endotoxin-induced uveitis in a TGF-sZ(1) transgenic (Tg) murine model. TGF-sZ(1) Tg mice were generated by micro injecting a gene constructed by fusing the mouse albumin enhancer/promoter and porcine TGF-sZ(1) cDNA. The eyes of Tg mice from two to 14 weeks of age were studied histologically. Tg mice, two to five weeks of age exhibited mild fragmentation of the lens fibers and retinal edema. No pathology was found from six to ten weeks of age, however, a progressive increased frequency of cataract was observed from 11 to 14 weeks of age. Plasma TGF-sZ(1) levels were much higher in Tg mice than age-matched wild type control littermates (wt). Endotoxin-induced uveitis (EIU) in six-to eight-week-old Tg and wt mice was induced by footpad injection of lipopolysaccharide (LPS). Mice were euthanized 24 hr after LPS injection, the eyes were collected for histology and serum assayed for IL-6 and TGF-sZ(1). There was a decrease in the mean numbers of infiltrating cells in Tg mice compared to wt mice. Serum IL-6 and TGF-sZ(1) were much higher in Tg mice. The authors concluded that expression of the TGF-sZ(1) transgene in the eyes may have effect on lens growth. Overexpression of TGF-sZ(1) results in little or no effect on the development of EIU. 相似文献
83.
HPLC法测定拉呋替丁及其片剂的含量 总被引:3,自引:0,他引:3
目的 建立拉呋替丁及其片剂的高效液相色谱含量测定法。方法 以Shim packODSC18为色谱柱 ,甲醇 0 2mol·L 1醋酸胺溶液 三乙胺 (70∶30∶0 1)为流动相 ,检测波长为 2 75nm。结果 线性系数r =0 9998,平均回收率为 99 6 % (RSD =1 5 % ,n =9)。结论 本方法简便、快速、准确 ,可用于拉呋替丁及其片剂的质量控制。 相似文献
84.
超声心动图对儿童完全性肺静脉异位引流诊断价值的探讨 总被引:2,自引:0,他引:2
目的 旨在评价超声心动图对完全性肺静脉异位引流 (TAPVD)的诊断价值。方法 对 1987年 9月至2 0 0 2年 11月收治的TAPVD患儿 70例进行分析。均有完整的临床及超声心动图资料 ,其中 35例施行了手术治疗。结果 70例TAPVD的解剖分型为 :心内型 5 2例、心上型 16例、心下型 2例 ,未发现混合型。 35例施行手术 ,32例与术前超声心动图的诊断一致 ;3例与超声心动图诊断不完全一致 ,其超声心动图诊断分别为 :三房心伴继发孔房缺、左房隔膜伴继发孔房缺、原发孔房缺伴卵圆孔未闭 ,而手术结果均显示为心内型TAPVD伴继发孔房缺。结论 超声心动图检查是诊断TAPVD重要且准确的方法 ,并能确定其分型 ,提供精确的解剖及血流动力学资料。在应用超声心动图诊断TAPVD时 ,应注意与三房心、左房隔膜等疾病进行鉴别。 相似文献
85.
Compromised kidney graft rejection response in Vervet monkeys after withdrawal of immunosuppressants tacrolimus and sirolimus 总被引:2,自引:0,他引:2
Chen H Peng J Luo H Loubeau M Wan X Xu D Qi S Vu MD Daloze P Fitzsimmons WE Bekersky I Peets J Sehgal SN Wu J 《Transplantation》2000,69(8):1555-1561
BACKGROUND: In nonprimates, organ allografts are often not rejected after withdrawal of immunosuppression. In this study, we examined whether such a phenomenon also occurs in primates. METHODS: Vervet monkeys were transplanted with renal allografts and treated for 60 days with tacrolimus, or tacrolimus plus sirolimus. The drugs were totally withdrawn on day 61. The survival of the monkeys was monitored, and their response to donor- or third party-derived alloantigens was examined in vivo and in vitro. RESULTS: The majority (80-100%) of the grafts survived for at least additional 30 days with no signs of acute rejection. The compromised rejection is donor-specific, because recipient monkeys failed to reject a donor-derived skin graft, but a third-party skin graft was rejected. In vitro mixed lymphocyte reaction and interleukin-2 production in the mixed lymphocyte reaction between the recipients and their donors or between the recipients and a third party had no discernable patterns, and thus did not reflect the in vivo status of the immune system. Although the recipients could not reject the graft acutely after drug withdrawal, the kidney grafts and the donor-derived skin grafts had pathological findings of chronic rejection. CONCLUSIONS: The rejection response of the monkeys to an established graft after withdrawal of immunosuppression is compromised. The compromised rejection is specific and is not due to a permanent alteration of the immune system by the initial drug treatment. The allografts are not inert but have low levels of interaction with the recipient immune system. 相似文献
86.
Recombinant human insulin-like growth factor-1 induces an anabolic response in malnourished CAPD patients 总被引:3,自引:0,他引:3
BACKGROUND: Insulin-like growth factor-1 (IGF-1) is an anabolic hormone that mediates most of the growth effects of growth hormone. This study tested the hypothesis that recombinant human IGF-1 (rhIGF-1) will induce an anabolic response in malnourished patients undergoing continuous ambulatory peritoneal dialysis (CAPD). METHODS: Six CAPD patients with protein-energy malnutrition underwent nitrogen balance studies in a clinical research center for 35 days each. Throughout the study, patients were maintained on their same CAPD regimen prior to hospitalization, and were fed a constant protein and energy intake that was similar to their diet prior to hospitalization. The first 15 hospital days were a baseline period; during the subsequent 20-day period, patients were given subcutaneous injections of rhIGF-1 (100 microg/kg/12 h), except for one patient who received 50 microg/kg/12 h for the first five days, followed by 100 microg/kg/12 h for the following 15 days. RESULTS: During the treatment with rhIGF-1, serum IGF-1 increased by about 100% (P = 0.03), and nitrogen balance became strongly positive (+2.0 g/day, P = 0.015 vs. baseline). This anabolic effect was observed within hours after commencing the rhIGF-1 treatment and was largely caused by a 20% decrease in peritoneal dialysate effluent nitrogen. There was a proportionate reduction in urine nitrogen and serum urea nitrogen. This decrease in nitrogen output was sustained during the entire 20 day of treatment with rhIGF-1. Serum phosphorus decreased significantly during the first several days of rhIGF-1 treatment, whereas serum calcium increased significantly during the rhIGF-1 treatment. Serum potassium and albumin did not change during the rhIGF-1 injections. There was no change in body weight and body composition, as assessed by anthropometry during the baseline or treatment phases of the study. Some patients exhibited minor possible adverse events that included a reduction in blood pressure and transient tachycardia. CONCLUSION: Injections of rhIGF-1 induce a strong and sustained anabolic effect, as indicated by a positive nitrogen balance in CAPD patients with protein-energy malnutrition. rhIGF-1 administration may be an effective method for treating malnutrition in maintenance dialysis patients. 相似文献
87.
纤维喉镜与核磁共振(MRI)在喉癌诊断中的应用 总被引:1,自引:0,他引:1
将25例喉癌的术前纤维喉镜检查和喉部MRI与手术、病理进行比较,结果提示:纤维喉镜是喉癌诊断的最基本和最重要手段,能对T1、T2声门癌作出准确分期;MRI对显示粘膜面肿瘤虽然并不重要,但能准确判断肿瘤对会厌前隙、声门旁隙、喉软骨及喉外的侵犯;两者作用互补,对喉癌的诊断、术前分期及手术方法的选择具有重要意义。 相似文献
88.
颗粒细胞瘤(GranularCelTumor,GCT)是一种罕见的肿瘤。常发生于舌、皮肤及皮下组织、乳腺等部位。呼吸道GCT发生率低,若累及呼吸道则以喉和支气管较多见。原发部位位于气管的GCT极少,截止到1986年英文文献仅有10例气管GCT报道,国内近13年未有气管颗粒细胞瘤报道,。本文报道1例30岁女性气管GCT患者,结合文献对气管GCT的组织发生、临床表现、病理特点、诊断与鉴别诊断以及治疗方法等问题进行讨论。 相似文献
89.
p16与C—myc在喉鳞状细胞癌中的表达意义 总被引:2,自引:0,他引:2
目的:研究p16和C-myc在喉鳞状细胞癌中的表达意义。方法:应从p16和C-myc单克隆抗体,通过免疫组织化学法检测6例正常喉粘膜和47例喉鳞癌中p16和C-myc的表达。结果:6例正常喉粘膜组织中未发现p16和C-myc蛋白阳性表达,47例喉鳞癌中p16和C-myc阳性表达率分别为48.9%(23/47)和57.4%(27/47),与性别、年龄和肿瘤发生的部位无相关性(P>0.05),与临床分期和病理分级相关(P<0.05);C-myc还与颈淋巴结转移相关(P<0.05)。结论:p16和C-myc蛋白阳性表达在喉鳞癌的发生和发展中起重要作用,可作为评价喉鳞癌预后的新指标。 相似文献
90.
嗅区粘膜放疗后可引起迟发性嗅觉障碍,为了解其机制,对放疗后嗅粘膜用透射电镜观察其超微结构改变。发现其上皮层变性嗅神经原增多;固有层内纤维母细胞增多,胞浆内含有大量粗面内质网和线粒体,在纤维母细胞周围有大量整齐排列的胶原纤维。放疗后嗅粘膜的纤维化是嗅觉障碍的原因之一。 相似文献